Brake with release



W E 5* E. H. HAVIE M9543 BRAKE WITH RELEASE Filed April 2e, 194e 2shetsneet 11.

#VVK/WNW? ANDREW H, HAV/,L3

Ey /6 M.

BRAKE WITH RELEASE Filed April 26, 1948 2 Sheets-Sheet 2 atentedl Apr.25, 195@ STATES P TE T FF ICE 2 Claims.

This invention has relation to a brake with release devised to beemployed in connection with a crankshaft of a machine, such, forexample, as a punch press, including a stationary lower member and amovable upper member adapted to be reciprocated relative to saidstationary lower member in response to operation of said crankshaft.

The movable upper member of a machine of character as above set forthordinarily is situated substantially at the upper limit of its upstrokewhen the machine is at rest. When said machine is set in motion, as, forexample, in response to depression of a foot pedal, its crankshaft ispower actuated to cause its movable upper meinber to make one downstrokeand one upstroke and released upon approach of said movable upper membertoward the upper limit of each upstroke, and a brake, commonly includinga brake drum on the crankshaft, operates upon release of said crankshaftto bring said movable upper member to rest at the upper limit of each ofits up strokes.

The object of the present invention is to provide in a machine includinga stationary lower member, a movable upper member and a crankshaftadapted to be operated by power actuated means to accomplish alternatedownstrokes and upstrokes of the movable upper member toward and awayfrom the stationary lower member and released from said power actuatedmeans upon approach of said movable upper member toward the upper limitof each of its upstrokes, a new and improved brake incorporating aconstruction and arrangement, or mechanism, adapted to be operative toremove braking tension from said crankshaft upon commencement of eachdownstroke of said movable upper member in response to operation of thecrankshaft by said power actuated means, maintain no braking tension onsaid crankshaft during substantially the whole of each downstroke andupstroke of the movable upper member in response to operation of thecrankshaft by said power actuated means and apply braking tension tosaid crankshaft when released from the power actuated means uponapproach of said movable upper member toward the upper limit of each ofits upstrokes adapted to cause the movable upper member to be brought torest when it reaches substantially the upper limit of each of itsupstrokes.

In the accompanying drawings forming a part Y of this specification,

machine including a stationary lower. member' and a movable upper memberadapted to be reciprocated relative to said stationary lower member inresponse to operation of a power actuated crankshaft of the machine andalso including a brake with release made according to the invention;

Fig. 2 is an enlarged end elevational View of the brake with release ofthe machine of Fig. 1 as it would appear from the left in said Fig. 1;and

Fig. 3 is a fragmentary side elevational View, partially in section, ofthe disclosure of Fig. 2 as it would appear from the right in said Fig.2, also disclosing a portion of the machine of Fig. 1.

With respect to the drawings and the numerals of reference thereon, idenotes a machine including a stationary lower member Il, a movableupper member l2 adapted to be reciprocated toward and away from saidstationary lower member, a crankshaft i3 suitably and convenientlyrotatably supported upon the frame of said machine and assembled withsaid movable upper member and a fly wheel or pulley lli on an endportion of said crankshaft adapted to be rotated by power actuated meansto in turn cause the crankshaft i3 to be rotated thus to cause saidmovable upper member to be reciprocated.

A brake drum l5 is rigidly iixed upon the crankshaft i3, at the endthereof opposite the ily wheel or pulley lli in the disclosure as made,and brake levers, designated I5 and il, respec-l tively, support brakelinings i8, i8 adapted to be pressingly engaged with and released fromdiametrically opposite surfaces of said brake drum i5. An end portion ofeach of the brake levers I6 and l? is rotatably mounted, for swingingmovement of said brake levers toward and away from the brake drum l5,upon a pivot pin is rigidly supported on the frame of the machine iii ata side of said brake drum, and the brake levers are of arcuateconfiguration. spaced apart, parallel end portions, represented 2B and2i, respectively, of the brake levers ie and il, at the side of thebrake drum i5 opposite the pivotal support i9, are slidably situated ona guide rod 22 between a head 23 on an end ci said guide rod and nuts2li adjustable upon an end portion of the guide rod opposite said head.Said guide rod 22 is disposed in perpendicular relation to the pivotalsupport I9.

An instrumentality for applying braking tension i to the brake drum I5,in response to forcible rotasaid brake drum, by release of said brakelevers, includes a cam 25 fixed upon the brake drum and disposedexteriorly of the brake linings I8, I8 in clearing relation to the brakelevers, an actuator 28 pivotally supported, as at 21, upon a part of thebrake lever I6 adjacent its end portion 28, and a roller 28 mounted on amain body part of said actuator' 26 in spaced relation to the pivotalsupport 21. Said pivotal support: 21 `is substantially alined with theAguide rod22 nfdirection transversely of the brake drum I and isdisposed in parallel relation to and at the side of said brake drumopposite the pivotal support I5, and said roller 28 is situated at theside of the end portion 2l opposite the en d portion 2li.y

The cam includes an exterior arcuate sur'- face 29 extendingcircumferentially'of the brake drum and forward and rearward obliquesurfaces, indicated and 3I, respectively, the former 'ex'- tendingoutwardly from about the periphery of the brake drum I5 to the forwardend of the arcuate surface -23 and the latter extending inwardly fromthe rearward end of said arcuate `surface 29 to about the periphery ofvsaid brake drum. u

The roller 28 and the main body part of the actuator 28 which supportssaid roller are situated exteriorly of and in clearing relation to thebrake linings and levers, and the cam 25and said roller 28 are disposedin alined relation in direction transversely of the brake drum I5. y

An extension piece 32, rigid with the main body part of the actuator 28and in spaced relationto the pivotal support 21 at the vside thereofopposite the brake drum I5, is offset interiorly of said main body p artand slidablyrsituated inspaced relation to the end portion 28 upon apart uof 'une guide rod 22 between ksaid end portion 20 and the nuts 24.n l

A compression coil spring 38, for actuating'the brake levers I5 and i1to cause braking tension to be applied to the brake drum I5, is situatedupon said guide rod v22 between said nuts 24 and the extension piece 32.

The arcuate surface 29 of the cam 25 can be n continuous throughout anypreferred arc, but desirably, said arcuate surface can be continuousthroughout an arc about as disclosed in Fig. 2 of the drawings.

The cam 25 is adapted to force the roller 28 outwardly once during eachrevolution of the brake drum I5, and the arcuate surface 249 of said camis adapted lto retain said roller 28 in its outwardly forced positionfor the wholev of the interval during'each revolution of said brake drumwhile said arcuate surface is engaged beneath said roller.Outwardforcing of the roller 28 will cause the actuator 26 to be swungoutwardly on the pivotal support 21 as an axis and the extension piece32 to be Vswung in direction toward the compression coil spring 33. Theconstruction and arrangement will be such that vthe forward obliquesurface 3U of the cam 25 upon riding under the roller 28 will causesaidroller to be swung outwardly a suicient distance so that when thearcuate surface 29 of said cam is engaged beneath said roller theextension piece 32 will be situated to urge the head l23 on the :guiderod v22 up against the end portion V2| of the brake lever I1 and lretainthe compression coil spring compressed betweensaidv extension 'pieceandthe nuts 2 4 Vthus to causesaid Vcompres- YYsion coil spring tobeloaded and/the brake linings of the brake lever to befresilientlypressed vagainst the brake drum I5. It will be apparent 4 that thecompression coil spring 33 when placed under connement, in the manner asset forth, simultaneously will exert resilient effort upon the brakelevers I8 and I1, through the instrumentality of the extension piece 32while retained by the cam 25 against rotative movement relative to saidbrake levers, the guide rod 22 and the head 23 and the nuts 24 on saidguide rod, adapted to causesaid brakelevers to be rotatably urgedtowardfeach other. The construction and ar.. rangement also will be suchthat when the cam A25 is removed from beneath the roller 28 the actuator26 will be capable of having free rotative V'-movement, in clockwisedirection in Fig, 2, to a sufcient extent to permit the compression coilspring 33 to be capable of having suflcient expansion to be `under zerocompression to exert no confining effort upon the brake levers tendingto apply braking tension to the brake drum I5.

The machine I0 is Vdisclosed in Fig. 1 of the drawings/as when at rest.the Imovable upper 'member I2 being `sub'stafntially Vatthe upl'er limitv:of its upstroke 'and the crankshaft I3 being in position vto start aIdowns'trcike of said movable uppermember. In Fig. -2 the brake drum I5uis in position as when saidcrankshaftis at rest,

as in said Fig. l, and the rearward end positionV of the arcuate surface29 of the cam 25 is engaged beneath the rolleru 28. KUp'on commencement-of each downstroke of the movable lupper member I2 'in 'response torotation of the crankshaft EIS, in the direction' of vthe'arrox'iv'inFig v2, by power :actuatedfmeans `(not shown) z ic'a'p'ited tobeapplied to said 'crankshaft through the inedium `of -the fly wheelorpulley I4, thel arcuate Vsiirfa'ceZe fwill be caused to travel 'fromy'beneath the rollefr 28 thus to cause confining effortupon the brakelevers 'and braking tension'on the brake drum tolbe removed. Duringkrotation of [the crankshaftby "said power actuated means while themovable upper member-l'2 is completing 'sub- "stantially `the whole ofeach 'of'its downstrokes and upstrokes the cam 25 willbeclear of theroller 28 so that the brake Alevers will be under no conning eifort andthe Abrake `drum will be under no braking tension. Y The extent of thearcof the arcuate'surface 29 will be such that thev forward 'end portion'of said arcuatesurfa'c'e 'will become engaged beneath said "roller28'when`power 5actuation 'of the crankshaft I3 is terminated byreleaseof said crankshaft from the power actuated 'means vupon approachofjs'aid movable upper member toward the upper limit ofeachof its'upstrokeS, and the r.construction andarrangeinent Awill be such that'the crankshaft will be brought to rest by application of brakingtension to the brake y drum I 5 in response to resilient confiningeffort imposed on the vbrake levers I6 and I1`wh`en v'the `movable uppermember reachesth'e upper limit of `eaclfrof its upstrokes and 'theca'm'25 is `situated relative to lthe roller 28 about asfdsvclosed inFig. 2 'of the drawings, Statedoth'erwise, braking action willbe appliedto the crankshaft `while the arcuate surface 29 is riding Vbe neath theroller 28,V andsaid crankshaft will be brought to rest while therearward Vendfpo'rtion of said 'arcuatesjurface is yetbeneath saidroller.

yThe 'brake with "release Vwhich "the 'invention presents 'Withholdsbrakingtension frO'in the brake drum is 'during substantiaiiyuie jwholeof the power actii'ite'dv portions of the 'downstrokes anu lipstick-'ssof uiejwatie flipper member I 2 when braking tension "is not requiredand in fact, 'detrimentalitogeinerent perauon -by reason si ure"factftha-brakeirieiion ill generates heat liable to become excessivethus to cause failure of lubrication in main bearings and burning out ofbrake linings. In short, the brake illustrated and described in thepresent application is adapted to function to bring the crankshaft I3 torest when released from power actuated means which drives saidcrankshaft, as well as to retain the crankshaft and the movable uppermember I2 in their intended positions while the machine I is at rest. Atall other times, save during the inconsequential interval the cam 25 isriding off of the rearward end of the arcuate surface 29 from itsposition as in Fig. 2, immediately after starting up of the machine, thenew and improved brake is inoperative.

rIhere is no positive connection between the brake actuator and thepower source. The brake is operated by action of the cam upon thecompression coil spring, and the construction and arrangement are suchthat the torque generated by the power source is of enough magnitude todrag the cam sufficiently with the brake in the on position to cause thecompression coi1 spring to bring the brake drum to rest.

What is claimed is:

1. A brake comprising a rotatably supported brake drum adapted to bepower actuated during the accomplishment of alternate downstrokes andupstrokes of a movable member and released upon approach of said movablemember toward the upper limit of each of its upstrokes, rst and secondbrake members adapted to be pressingly engaged against and released fromopposite surfaces of said brake drum, means supporting said rst andsecond brake members for movement toward and away from said brake drum,a cam rigid with said brake drum and having a circumferentiallyextending arcuate surface, an actuator pivotally supported upon a partof said first brake member at a side of said brake drum opposite saidsupporting means for the rst and second brake members for swingingmovement toward and away from said second brake member, a roller mountedon said actuator in position to be engaged by the arcuate surface ofsaid cam, a guide rod adjacent said actuator at a side thereof oppositesaid brake drum and in perpendicular relation to the brake drum, meanssecuring said guide rod to a part of said second brake member at a sideof said brake drum opposite said supporting means for the first andsecond brake members, an extension piece rigid with said actuator andslidably arranged on said guide rod in spaced relation to the secondbrake member, a stop on said guide rod in spaced relation to saidextension piece at a side thereof opposite the second brake member, anda compression coil spring on the guide rod between said extension pieceand said stop, said arcuate surface of the cam being adapted to becomeengaged beneath said roller to cause said actuator to be rotated tocause said compression coil spring to be loaded thus to cause said firstand second brake members to be pressingly urged against said brake drumand to be removed from engagement beneath said roller to release thecompression coil spring to cause it to become unloaded and the rst andsecond brake members to be released from pressing engagement againstsaid brake drum.

2. A brake comprising a rotatably supported brake drum adapted to bepower actuated during the accomplishment of alternate downstrokes andupstrokes of a movable member and released upon approach of said movablemember toward the upper limit of each of its upstrokes, first and secondbrake members adapted to be pressingly engaged against and released fromopposite surfaces of said brake drum, means supporting said nrst andsecond brake members for movement toward and away from said brake drum,a cam rigid with said brake drum and having a circumferentiallyextending arcuate surface, an actuator pivotally supported upon a partof said first brake member at a side of said brake drum opposite saidsupporting means for the first and second brake members for swingingmovement toward and away from said second brake member, means supportedby said actuator in position to be engaged by the arcuate surface ofsaid cam, an elongated element adjacent said actuator at a side thereofopposite said brake drum and secured to said second lever inperpendicular relation to the brake drum, a member rigid with saidactuator at the side thereof opposite said brake drum and slidablyarranged on said elongated element at a side of said rst brake memberopposite said second brake member, a stop rigid with said elongatedelement at a location in spaced relation to said member at a sidethereof opposite said second brake member, and a compression coil springon said elongated element between said member and said stop, saidarcuate surface of the cam being adapted to become engaged beneath saidmeans to cause said actuator to be rotated toward said compression coilspring to cause it to be loaded thus to cause said rst and second brakemembers to be pressingly urged against said brake drum and to be removedfrom engagement beneath said means to release said compression coilspring to cause it to become unloaded and the rst and second brakemembers to be released from pressing engagement against said brake drum.

ANDREW H. HAVIR.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 704,534 Greenwood July 15, 1902FOREIGN PATENTS Number Country Date 17,740 France July 31, 1912 387,200Great Britain Feb. 2, 1933 536,228 France Apr. 28, 1922

